Expansion-chuck



C. LEA.

EXPANSION CHUCK. APPLICATION FILED DEC. 13, 1918.

Patented Mar. 30, 1920.

2 SHEETS-SHEET I.

Inventor. Ciwzrlas Lew, by M C. LEA.

EXPANSION CHUCK.

A-PPLlCATlON FILED DEC. 13, I918- 1,335,714. I Patented Mar. 30, 1920.

2 SHEETS-SHEET 2.

CHARLES LEA, 0F DORCHESTER, MASSACHUSETTS, ASSIGNOR T0 ANDREW TERKELSEN,OF NEWTON HIGHLANDS, MASSACHUSETTS, AND CARL J. WENNBERG, OF EASTMILTON, MASSACHUSETTS.

EXPANSION-CHUCK.

Specification of Letters Patent. 7

' Patented Mar. 30,

Application filed December 13, 1918/ Serial No. 267,028.

to expansion chucks and has for its object the production of a device ofthis character which will be simplified in construction and'moreefficient in its operation.

The invention consists in providing the head of the chuck with a singleimmovable member of hardened steel which will-coact with the inner endsof all of the screws of the. chuck and prevent end movement thereof.

.The invention further consists in certain novel features ofconstruction and arrangement of parts whlch Wlll be readily understoodby reference to the description of the drawings and to the claimshereinafter given. 7 V V For the purpose of illustrating the invention,one preferred form thereof is illustrated in the drawings, this formhaving been found to give satisfactory and reliable results, although itis to' be understood that the variousinstrumentalities of which theinvention consists can be variouslyarranged and organized, and that theinvention is not limited to the precise arrangement and organization ofthese instrumentahties as herein shown and descrlbed except asrequiredby the scope of the appended claims.

Of the drawings: Figure 1 represents a plan of a chuck embodying theprinciples of the present inven tion, two of the slides thereof beingshown removed.

Fig. -2 represents an elevation of the same,

Fig. 3 represents a vertical section thereof on line 3, 3 on Fig. 1.

Fig. 1 represents a perspective of theinsertedscrew-holding ring, and

Fig. 5 represents an end view of one of the slide-adjusting screws.-

Similar characters indicate like. parts throughout the several figuresof the draw- ,ings.

In the drawings, 10 is the head of the chuck having formed in one face,thereof, a

plurality. of radial slots 11, the side walls provided 1' of eachofwhich are parallel and with a plurality of grooves 12. o Each slot 11has positioned therein a slidmg member 13, the side walls of which havea plurality of ribs 14: extending into the grooves 12. 1 7

These members 13 are adapted to be moved toward and from the center ofthe head'lO and the plurality of ribs projecting from the side wallsinto the grooves 12 retain said members always in the same plane andprevent any lateral movement thereof which would be very objectionablewhen the chuck is in use.

Each sliding member 13 is provided in its inner face with a threadedrecess 15, the threads of each of which engage with the threads of ascrew 16,positioned in a semicylindrical recess 17 in the bottom of aslot 11.

Each screw 16 is provided at, its inner end with an annular peripheralgroove 18 forming a reduced shank 19 and collar 20. r o

In the rear end of the head 10 is driven an annular member 21 ofhardened steel, this member having in its inner end a plurality ofsemi-cylindrical depressions 22 in each of which is positioned a shank19 of a screw 16. 1 V

Adjacent to each depression 22, the inner face of the member 21 isflattened at 23 to form a suitable bearing surface for the inner end ofthe collar 20. 1

The opposite walls of the annular peripheral groove 18 bearing againstthe inner and outer walls of the annular member 21, prevent any endmovement of the screws 16.

When either of these screws 16 are rotated, the threads thereof engagingthe threads of the recess 15 in a sliding member 13, will impart endmovement to said sliding member, the direction of movement dependingupon the direction of rotation ofsaid screw 16.

Itis obvious that the opposite walls of the grooves 18 will take-care ofanyend thrust of thescrews 16 as'they are rotated sliding members 13,

Moreover, when grooves are cut'into the screws midway of the threadedportion thereof, the sharp ends of the threads on opposite sides of thegroove are liable to cut into the threads of the recess 15-and injurethe same.

In the present construction this objection is entirely overcome.

By having a single member, such as the ring or annular member 21, toprevent end movement of all of the screws 16, the construction of thechuck is greatly simplified and a more efiicient chuck may be made at agreatly reduced. cost.

Moreover, as the depressions 22 serve to position the inner end of thescrews 16, these SCFJVS will always be maintained. radial to the centerof the head 10.

it is obvious also that the depressions 22 may be more readily andaccurately formed in the small inserted ring or annular member 21 thanthey could be formed in the head itself and at less expense. 7

Another advantage in using the ring or annular member 21, is that it maybe hardened and thereby out-last con ructions where the end thrust istaken care of by shoulders formed on thehead "l0.

Should the ring become worn or damaged it may be removed quickly andreplaced by another without in any manner affecting the other parts ofthe chuck.

Owing to the reduced number of parts used, the chuck may be more readilyassembled thereby saving time and labor.

it is believed that from the foregoing description, the operation andmany advantages of the present invention will be readily understood.

Having thus described my claim: 7

1. The combination of a head having in oneface a plurality of radialslots having continuousunbroken walls and provided in its opposite facewith a central cylindrical chamber; slide for each slot having athreaded. rec ss formed in its inner faceand invention, I

V novided with a plurality of Work-engaging shoulders on its outer faceformed integral therewith; a revoluble screw in each. slot rroactingwith the threads of each recess; and an annular member driven into acentral chamber in the inner end of said head and coacting with all ofsaid screws to prevent end movement thereof 1n either direction.

2. The combination of a head having a plurality of radlal slots in oneface thereof having continuous unbroken walls; a slide for each slothaving a threaded recess formed in its inner face and provided withaplurality of work-engaging shoulders on its outer face formed integraltherewith; a revoluble screw in each slot coasting with the threads ofeach recess and provided at its inner end with a flange of less diameterportion. of said and an annular peripheral said flange and the threadedscrew; and an annular mem ber driven into the inner end of said head andhaving in its inner end a plurality of depressions, the walls of eachdepression coacting with an annular peripheral groove in a screw toprevent end movement thereof in. either direction.

The combination of a head having in one face a plurality of radial slotshaving continuous unbroken walls and provided in its opposite face witha central cylindrical chamber, each slot being provided with a pluralityof grooves in the side walls therethan said screw groove between of; aslide for each slot having a threaded recess in its inner face and sideribs extending into said grooves, said slide also vhaving Japlurality ofworloengaging shoulders on its outer face; a revoluble screw in eachslot the threads of which extend to the periphery of said head and coactwith. the threads of each recess; and a single member fixedly secured insaid central chamber and coacting with all of said screws to prevent endmovement thereof in either direction.

4. The combination of a head having a plurality of radial slots in oneface thereof having continuous unbroken semi-cylindrical bottoms; slidefor each slot having a threaded recess in its inner face and a pluralityof work-engaging shoulders on its outer face; a member in each slotrevoluble in contact with the wall of its semicylindrical bottom andprovided with continuous threads extending to the outer end thereof andcoacting with thethreads of each recess; and a single member of hardenedsteel fixedly secured in a central chamber in the inner end of said headand coacting'with all of said screws to prevent both end and lateralmovementthereof.

V5. The combination plurality of radial slots aslide for each slothaving a threaded recess in its inner face and a plurality ofworkengaging shoulders on its outer face; a revoluble screw in each slotcoacting with the threads of each recess and provided with a flangedhead at its inner end ofless diameter thanthe threaded portion of saidscrew and an annular peripheral groove between said. head and saidthreaded portion and an annular member secured in a central chamher inthe inner end of said head and having its inner end depressions providedwith parallel flat bearing surfaces at opposite ends thereof, saiddepressions coacting with the peripheral grooves to prevent end movementof said screws in either direction.

6. The combination of a head having at one end av cen'ral cylindricalopening and a plurality of radial slots extending from said opening tothe periphery of said head and at the other end a larger cylindricalchamof a head having a in one face thereof;

ber; a slide in each slot having a threaded recess 111 its inner faceand a plurallty of work-engaging shoulders onlts outer face;

a revoluble screw in each slot coacting with 7. The combination ofa headhaving at one end a central cylindrical opening and a plurality ofradial slots having continuous unbroken semi-cylindrical bottomsextending from said opening to the periphery of said head and at theother end a larger cylindrical chamber; a slide in each slot having athreaded recess in its inner face and a plurality of work-engagingshoulders on its outer face; a revoluble screw positioned in cont-actwith the semi-cylindrical bottom of each slot coacting with the threadsof each recess and provided with an annular peripheral groove at itsinner end; and an annular member secured to said head within saidchamber and having at its inner end depressions, the walls of which arepositioned in said annular grooves. r

8. The combination of a head having in one face thereof, a centralopening and a plurality of radial slots extending from said opening tothe periphery of said head and each having a semi-cylindrical bottom ofthe same diameter throughout the length of said slot; a revoluble screwin each slot of the same diameter as the semi-cylindrical bottom of saidslot and provided with a reduced inner end having an annular groovetherein; a slide in each slot having a threaded recess in the inner facethereof the threads of which coact with the threads of said screw; andan annular member driven into said opening and provided with de-.pressions in the inner end thereof, the walls of which are positioned insaid annular grooves and prevent said screws from moving endwise. v

9. The combination of a head having in one face thereof, a central.opening and a plurality of radial slots with cal bottoms of the samediameter throughout their length and extending from said opening to theperiphery of said head, which head is provided with a cylindricalchamber in the opposite face thereof; a' revoluble screw in each slot ofthe same diameter as the semi-cylindrical bottom of said slot andprovided with a reduced inner end having an annular groove therein; aslide in each slot having a threaded recess in the inner face thereof,the threads of which coact with the threads of said screw; and anannular mem ber driven into said cylindrical chamber and provided withdepressions in the inner end thereof, the walls of which are positionedin said annular grooves and prevent said screws from moving endwise,'theinterior diameter of said annular member being greater than the diameterof said central opening.

Signed by me at 4 Post Office I CHARLES LEA. I \Vitnesses:

l VALTER E. LoMBAnD, i MAZIE W. KIMBALL.

semi-cylindri- Square, Boston, Mass, this 12th day of December,

